Truth Predicate: the truth predicate of a language is the "is true" expressed in this language. Its allowance can be empirically justified or attributed to the statement on the basis of the logical form. According to the redundancy theory, the truth-predicate is fundamentally superfluous. According to W.V.O. Quine (Quine, Philosophie der Logik, 2005, p. 33), the truth predicate is merely used for generalization. For example, all sentences of a particular form are true. A language containing its own truth-predicate is semantically closed. In such a language, semantic paradoxes are possible. See also expressiveness, circularity, semantic closeness, truth, truth definition, redundancy theory, self-reference, paradoxes._____________Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments.